Conventionally, an existing work vehicle has a front loader attached to the front of a tractor.
This work vehicle includes a main frame disposed in a lateral front portion of a tractor body. The front loader has a boom pivotally connected at a rear end thereof to an upper portion of the main frame to be vertically swingable, a boom cylinder for swinging the boom, a bucket pivotally connected to a forward end of the boom to be swingable, and a bucket cylinder for swinging the bucket.
The work vehicle further includes a boom control valve for controlling the boom cylinder, a bucket control valve for controlling the bucket cylinder, and a single control lever for operating the spools of the boom control valve and bucket control valve (Japanese Patent Application JP2001-140276 A and Japanese Patent Application JP10-280473A).